Importance: Lymphovascular invasion (LVI) is a poor prognosis pathologic feature in pancreatic ductal adenocarcinoma (PDAC) patients. Neoadjuvant therapy may bring survival benefits to these patients.

Objective: To construct a preoperative model which could predict LVI in PDAC patients and further validate it in other cohorts.

Design, Setting, and Participants: Patients from 3 three tertiary hospitals were included in this study. Univariate and multivariate Logistic regression analyses were conducted to define independent prediction factors of LVI. A nomogram was constructed based on the result of multivariate analysis.The predictive value of the model was assessed using receiver operating characteristic (ROC) curves and the maximum Youden index of the ROC curve was defined as the cut-off point. The calibration plot was utilized to assess the concordance of the model. The decision curve analyses (DCA) were applied to estimate the clinical benefit of using this model to predict LVI.

Inclusion Criteria:

• Patients who were pathologically diagnosed as PDAC and received curative surgery.

Exclusion Criteria:

• Patients with distant metastasis; Patients who received neoadjuvant therapy; Patients with a survival time of less than 1 month.

Patients who were pathologically diagnosed as PDAC and received curative surgery.